Posts with «photoresistor» label

Solar Panel System Monitoring Device Using Arduino

[Carl] recently upgraded his home with a solar panel system. This system compliments the electricity he gets from the grid by filling up a battery bank using free (as in beer) energy from the sun. The system came with a basic meter which really only shows the total amount of electricity the panels produce. [Carl] wanted to get more data out of his system. He managed to build his own monitor using an Arduino.

The trick of this build has to do with how the system works. The panel includes an LED light that blinks 1000 times for each kWh of electricity. [Carl] realized that if he could monitor the rate at which the LED is flashing, he could determine approximately how much energy is being generated at any given moment. We’ve seen similar projects in the past.

Like most people new to a technology, [Carl] built his project up by cobbling together other examples he found online. He started off by using a sketch that was originally designed to calculate the speed of a vehicle by measuring the time it took for the vehicle to pass between two points. [Carl] took this code and modified it to use a single photo resistor to detect the LED. He also built a sort of VU meter using several LEDs. The meter would increase and decrease proportionally to the reading on the electrical meter.

[Carl] continued improving on his system over time. He added an LCD panel so he could not only see the exact current measurement, but also the top measurement from the day. He put all of the electronics in a plastic tub and used a ribbon cable to move the LCD panel to a more convenient location. He also had his friend [Andy] clean up the Arduino code to make it easier for others to use as desired.


Filed under: Arduino Hacks

Lightefface Makes Music with Both Touch and Light

Kacper Ziemianin made a simple piano keyboard with an Arduino and some photoresistors. But it's what he does with the data that makes beautiful music.

Read the full article on MAKE

MAKE » Arduino 18 Feb 20:30

Tracking Solar Brightness with a Homemade Sun Logger

The Sun Logger, a data logging device, combines several components we’ve used in previous Weekend Projects. You may recognize the light-sensitive photoresistor (Optical Tremolo Box) and the Arduino Uno microcontroller (Touchless 3D Tracking Interface). These parts, when combined with a 74AHC125 Level Shifter and SD card socket mounted on a homemade “shield,” will record the levels of light shining down on your project box. That data, recorded every 15 seconds to the SD card, can be exported later to any popular spreadsheet software and graphed, giving you a visual representation of light changes over time. This data could aid in knowing where best to plant a garden, or simply to understand changes of light intensity throughout the seasons in your micro-climate.

And while this project is readymade for recording levels of sunlight, the Arduino has a total of six analog inputs (labeled A0 – A5) and could easily record other variables. For example temperature, motion, or barometric pressure. Makers looking for a mid-level Arduino build, or knowledgeable coders looking to solder together their first homemade shield, the Sun Logger is a great project to build!


Filed under: Arduino, MAKE Projects, Weekend Projects

Led as light sensor [Arduino]

If you connect led in the opposit way he can act as light sensor:

positive leg to analog pin

negative leg to 5V

You can use that for some things, but he not sensetive as LDR,

ןf you use a for example a green led he not "see" well red light

If you use charlieplexing method you can control one led to light and as a light sensor.

The idea is like this:

Two wires connect the led to two analog pins.

To light the led you set the two analog pins as digital output and one high one low. 

read more